Method of and apparatus for supporting or guiding strip material



y 16, 1953 s. s. CARLISLE ETAL 3,097,971

METHOD OF AND APPARATUS FOR SUPPORTING 0R GUIDING STRIP MATERIAL Filed Nov. 9. 1960 2 Sheets-Sheet 1 INVENTQRS J? $.Car/As/e B 6. H 5o a// ATTORNEYS y 1963 s. s. CARLISLE ETAL 3,097,971

METHOD OF AND APPARATUS FOR SUPPORTING OR GUIDING STRIP MATERIAL Filed Nov. 9, 1960 2 Sheets-Sheet z INVENTORQ S. S. Car/isle BY GM. Boxall M MM ATTDE N EYS 3,097,971 METHOD OF AND APPARATUS FOR SUPPORTING OR GUIDING STRIP MATERIAL Samuel Skipton Carlisle and Genefer Margaret Boxall, London, England, assignors to The British Iron and Steel Research Association, London, England Filed Nov. 9, 1960, Ser. No. 68,226 15 Claims. (Cl. 134-15) This invention relates to the support or guidance of strip material, such as, for example, steel strip passing through an electrolytic tinning line, continuous annealing line or the like.

According to one aspect of the present invention there is provided a method of supporting or guiding strip, material which comprises introducing a supply of pressurized fluid between a surface, across which strip material is caused to travel, and the adjacent surface of the strip material, whereby the strip material is maintained out of contact with said surface.

According to another aspect of the present invention there is provided apparatus for supporting or guiding strip material Comprising a support member, and means for introducing a supply of pressurized fluid through said member to a support surface thereof.

The above method and apparatus of the present invention provide, therefore, a low friction bearing. Furthermore, it is possible to avoid or reduce differential tensions in parts of or the whole of, strip material without adjusting and maintaining the adjustment of the surface speeds of a number of rollers, as is usually the case. Also changes of strip speed may be made without difficult problems of roller speed adjustment.

Application of the invention is particularly suitable for supporting and guiding materials, such as ferrous strip for tinplate manufacture, which require a high standard of surface cleanliness and surface finish.

In order that the present invention may be more clearly understood, the same will now be more fully described by way of example with reference to the accompanying drawings, in which:

FIGURE 1 illustrates diagrammatically one embodiment of the invention,

FIGURE 2 shows a modified support member for the embodiment of FIGURE 1,

FIGURES 3 and 4 show an enlarged, fragmentary side and plan view, respectively, of one form of support member.

FIGURE 5 illustrates alternative forms of support members, and

FIGURE 6 illustrates a preferred feature of support members according to the invention.

In the embodiment of FIGURE 1, means are provided for guiding a strip of material 1 'along a serpentine path. Such an arrangement meets a common requirement where, for example, a length of strip is to be contained for a period of time in a gaseous or liquid environment within a treatment vessel or chamber of reasonable dimensions. Fixed support members 2 are located at each bend position, each member having a convexly shaped support surface perforated with a number of holes through which a fluid, such as air, for example, is forced towards the strip. Pressurized fluid is trapped between the support surface and the strip for a suflicient time to form a cushion on which the strip floats while being pulled through the apparatus by draw rolls 3.

Where the strip is being pushed towards the support members, as opposed to, or in addition to being drawn away from them, the members may take the form shown in FIGURE 2. Here, the member 4 has a concavely curved support surface towards which the strip is driven by rolls 5. Preferably, a co-operating convexly curved United States Patent 0 3,097,971 Patented July 16, 1963 member 6 is also employed with member 4 as shown, to form a channel for passage of the strip and to provide increased control over the strip as it passes that point. Furthermore, the spacing between members 4 and 6 may be increased at the entrance to the channel, as illustrated, to facilitate entry of the strip.

Various arrangements may be used to supply fluid to the support surfaces. For example, in FIGURES 3 and 4 which show enlarged views of a convexly curved support member, a series of orifices 7 are provided near the longitudinal edges of the supporting part" 8. These orifieslead from a cavity 9 to which fluid is supplied at the appropriate pressure.

Further orifices 10 are provided towards the centre of the support surfaces and may be fed with fluid at lower pressure than orifices 7. Alternatively, where a common cavity is employed for supplying all of the orifices, differential orifice outlet pressures may be obtained by suitable design of the orifices themselves.

In another arrangement for supply of fluid to the support surfaces use is made of slit orifices as illustrated in FIGURE 5, for example.

The embodiment of FIGURE 5(a) only makes use of peripheral slit orifices 11, while those of FIGURES 5(b) and 57(c) show how additional slit orificeslz may be disposed to obtain increased support in the case of heavy strip material or wide material more properly regarded as of sheet form.

If desired the slit orifices may contain discontinuities instead of being continuous as shown in FIGURE .5. However, such discontinuities should generally be small in comparison with the required clearance between the support surface and supported material.

Clearly other variations of orifice form and disposition are possible and one such example is a combination of peripheral slit orifices and conventional circular orifices disposed in the central region of the support surface such as the orifice 10 of FIGURE 4.

Preferably the peripheral orifices, be they of circular, slit, or other form are angled to direct fluid towards the centre of the support surface as illustrated by FIGURE 6. This enhances the cushion effect of the fluid and delays the escape of fluid from between the support surface and supported material. Also, this angle may be varied as between the input and output sides with respect to the strip to take account of any slipstream effect set up by the strip motion. A

The positioning of the orifices, their design and size, and the pressure of fluid applied to them are all factors which may be varied as appropriate to achieve the optimum use of the fluid employed according to the weight of strip to be supported, its dimensions and flatness.

The pressure of fluid may be adjusted in any event to vary the clearance between the strip and support surface as demanded by surface conditions or thickness of material. Thus, the fluid pressure may be increased temporarily to take account of increased strip thickness in the form of a lap joint, for example.

The invention may be applied in processes involving thermal or chemical treatment of strip by employing bearing fluid of suitable composition and temperature. In particular, the invention may be used for guiding and supporting tinpl ate during drying after wet treatment or during flash heat brightening of electrolytic tin coating.

The strip may also be used for guiding and supporting strip during continuous annealing, or any thermal or chemical or thermo-chemical process in a vapor or gas environment, or during any cleaning or surface treatment process in a liquid environment.

The invention also finds application in the temporary storage means for moving strip'commonly referred to as reservoirs.

Although the above description refers almost exclusively to support or guidance of strip material, the expression strip material, also used in the claims hereinafter, is intended to include wide elongate material of various kinds which may sometimes be referred to as sheet material whether it be in continuous form or in a discrete sheet form.

In the case of a discrete sheet, the invention may be applied to a support table and the supporting jets switched on automatically, by photoelectric means, for example, as the sheet passes over successive sections of the table.

We claim:

1. A method of supporting an article which comprises introducing a supply of pressurized fluid through a surface, across which the article is caused to travel, to flow between the surface and the article whereby the article is maintained but of contact with the surface, the fluid being supplied at least in jets originating at the periphery of said surface and angled inwardly relative to the normal between said surface and the path of the article thereacross.

2. A method of supporting strip material in accordance with claim 1 which comprises employing a different angle for fluid jets first encountered by the material in its travel across said surface from those last encountered thereby, whereby any undesirable effect of the slipstream associated with said material on said fluid supply is substantially reduced.

3. A method of supporting an article in spaced relation to a support surface therefor which comprises forming a curtain of moving fluid directed from said support surface towards said article, and providing further supply of fluid from the support surface within the boundary of said curtain and at different pressure from the curtain fluid, which curtain and further supply form and maintain between said surface and said article and within the boundary of said curtain a cushion of pressurized fluid which tends to maintain the spaced relation between said surface and said article.

4. Apparatus for supporting an article, said apparatus comprising a support member having a support surface for cooperation with a surface of the article and which member is provided with inwardly angled port means disposed substantially around the periphery of said support surface for supply of pressurized fluid therethrough away from and inwardly of said support surface to provide at least one curtain of fluid forming and maintaining within a space between the cooperating surfaces defined by said curtain at least one cushion of pressurized fluid.

5. Apparatus for supporting an article comprising a support member having a support surface disposed closely adjacent the path of the article, first port means disposed substantially around the periphery of said surface for supply of pressurized fluid towards said path to form a fluid curtain, second port means disposed in said member within the area bounded by said first port means for addi tional supply of fluid towards said path, and fluid supply means for supplying fluid to said second port means at a lower pressure than to said first port means.

6. Apparatus for supporting an article comprising a support member having a support surface disposed closely adjacent the path of the article, first port means disposed substantially around the periphery of said surface for supply of pressurized fluid towards said path, and second port means disposed in said member within the area bounded by said first port means for additional supply of fluid towards said path, said first and second port means being respectively dimensioned for delivery of fluid received from a common fluid source at a higher pressure through said first port means than through said second port means.

7. Apparatus for supporting and guiding strip material along a curved path comprising two support members each having a support surface disposed closely adjacent the path of said material, and each member being provided with port means disposed substantially around the periphery of its respective support surface for supply of pressurized fluid therethrough towards said path to form a fluid curtain which forms and maintains a cushion of pressurized fluid within the space defined by the material, the support surface and the fluid curtain, a first one of said members having a support surface of convex form, the second one of said members having a support surface of concave form, and the two members being located with their support surfaces in mutually spaced and facing disposition on opposite sides of said path to provide a channel for passage of strip material therethrough along said path.

8. Apparatus according to claim 7 wherein the form and relative disposition of said support members is such as to provide a channel therebetween which is divergent at least one end thereof to facilitate entry of strip material into such channel.

9. Apparatus for supporting a moving article comprising a support member having a support surface for cooperation with a surface of an article moving thereacross, inwardly angled first port means disposed adjacent at least the side peripheries of said support surface relative to the path of the article for supply of pressurized fluid away from and inwardly of said support surface to provide first fluid curtains, and second port means disposed in said member in at least two lines transverse said support surface relative to the path of the article for supply of pressurized fluid away from said support surface to provide second fluid curtains, whereby said first and second fluid curtains form and maintain a pressurized fluid cushion in each space between the cooperating surfaces and defined by such curtains to support the article during movement across said support surface.

10. Apparatus according to claim 9 comprising at least one third port means disposed in said member in a line substantially parallel to the path of the article and intermediate said first port means for supply of pressurized fluid therethrough away from said support surface, to provide a third fluid curtain.

11. Apparatus for supporting a moving article comprising a support member having a support surface for cooperation with a surface of an article moving thereacross, first port means disposed adjacent at least the side peripheries of said support surface relative to the path of the article for supply of pressurized fiuid therethrough at a first fluid pressure to form fluid curtains, and second port means disposed in said member for supply of pressurized fluid through said support surface intermediate said fluid curtains and at a second fluid pressure lower than said first fluid pressure.

12. In a process line for moving strip material a device having a support surface for cooperation with a surface of strip material to be conveyed thereacross and which device is provided with inwardly angled port means adjacent the periphery of said support surface for supply of pressurized fluid therethrough away from and inwardly of said support surface to provide at least one curtain of fluid forming and maintaining within a space between the cooperating surfaces defined by said curtain at least one cushion of pressurized fluid.

13. In a process line for moving strip material a device having a support surface for cooperation with a surface of strip material to be conveyed thereacross, first port means disposed adjacent the periphery of said support surface for supply of pressurized fluid therethrough to form at least one fluid curtain, second port means disposed in said member within the area bounded by said first port means for additional supply of pressurized fluid therethrough, and fluid supply means for supplying fluid at a lower pressure through said second port means than through said first port means.

14. In a process line for moving strip material a device system for supporting and guiding the material including a plurality of support members each having a support surface for cooperation with a surface of the material to be conveyed thereacross and at least one of which support surfaces is of curved form, wherein each support member is provided with inwardly angled port means adjacent the periphery of its support surface for supply of pressurized fluid therethrough away from and inwardly of the support surface to provide at least one curtain of fluid forming and maintaining within a space defined by the support surface, the strip surface and the curtain at least one cushion of pressurized fluid.

'15. In a process line for moving elongate material a device system for supporting and guiding the material including a plurality of support members each having a support surface for cooperation with a surface of the material to be conveyed thereacross and at least one of which support surfaces is of curved form, first port means disposed adjacent the periphery of each support surface for supply of pressurized fluid therethrough at a first fluid pressure to form at least one fluid curtain, and second =por-t means disposed in each support member within the area bounded by the respective first port means for additional supply of pressurized fluid therethrough at a second fluid pressure lower than said first fluid pressure.

References Cited in the file of this patent UNITED STATES PATENTS -821,250 Miller May 22, 1906 1,844,798 Schroeder Feb. 9, 1932 2,418,386 Wood Apr. 1, 1947 2,689,196 Daniels Sept. 14, 1954 2,900,991 Arnold Aug. 25, 1959 2,919,706 William Jan. 5, 1960 2,993,492 Mains July 25, 1961 FOREIGN PATENTS 585,073 Canada Oct. 13, 1959 

1. A METHOD OF SUPPORTING AN ARTICLE WHICH COMPRISES INTRODUCING A SUPPLY OF PRESSURIZED FLUID THROUGH A SURFACE, ACROSS WHICH THE ARTICLE IS CAUSED TO TRAVEL, TO FLOW BETWEEN THE SURFACE AND THE ARTICLE WHEREBY THE ARTICLE IS MAINTAINED OUT OF CONTACT WITH THE SURFACE, THE FLUID BEING SUPPLIED AT LEAST IN JETS ORIGINATING AT THE PERIPHERY OF SAID SURFACE AND ANGLED INWARDLY RELATIVE TO THE NORMAL BETWEEN SAID SURFACE AND THE PATH OF THE ARTICLE THEREACROSS. 